In order to direct and concentrate the radiant heat emitted from the duct surface it is known to provide reflectors, typically of sheet metal, mounted adjacent to the duct, e.g. above it if the appliance is mounted overhead to direct the heat downwards.
It is also known to provide bodies of thermal insulating material shielding the duct on the side remote from the space to be heated, examples of such constructions being described in GB-A-2119075, GB-A-2108260, GB-A-1448073, EP-A-0261639 and US-A-4727854.
The object of the invention is to provide improvements in radiant tube heating appliances giving greater efficiency.
According to the invention there is provided a radiant tube heating appliance as defined in claim 1 of the appended claims.